Is abnormal glucose tolerance or diabetes a risk factor for knee, hip, or hand osteoarthritis? A systematic review

Diabetes (DM) and osteoarthritis (OA) are two common co-existing chronic conditions. However, whether this is due to shared risk factors or may differ between joints is unclear. We performed a systematic review to determine whether abnormal glucose metabolism is a risk factor for knee, hip and hand OA, separately, independent of age and obesity. A systematic search of Ovid Medline and EMBASE was performed from inception until October 2016 to identify studies relating glucose metabolism to osteoarthritis-related outcomes. Studies were included if they related DM and OA and the knee, hip, or hand were examined separately. In the structured synthesis, objective measures of DM and adjustment for age and obesity were also required. Of the 40 included studies, 28 examined the knee, nine the hip and 14 the hand. Five studies with a longitudinal component used objective measures of DM (blood glucose) and knee OA (radiography or joint replacement) and adjusted for age and obesity (21,299 participants). Of these, three found no association, one found a reduction in risk and one, which adjusted for the presence but not magnitude of obesity, found an increase in risk. Of the longitudinal studies examining the relationship between DM and OA that accounted for obesity, none provided evidence of an independent relationship between DM and hip (2 studies) or hand OA (1 study). There is little evidence to suggest that impaired glucose metabolism is a risk factor, independent of obesity, for knee OA and no evidence that impaired glucose metabolism is an independent risk factor for hip or hand OA.